Set reason for saved password pings if SBER is disabled

In UMA metrics PasswordProtection.RequestOutcome.AnyPasswordEntry, the
Unknown bucket is abnormally high. The reason is that "reason" is not set
when saved password is reused and SBER is disabled.

Bug: 1016540
Change-Id: I382e516f664cbd7b514c0005f4f90e6df607da45
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1888724Reviewed-by: Daniel Rubery <drubery@chromium.org>
Commit-Queue: Xinghui Lu <xinghuilu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#710858}

chrome/browser/safe_browsing/chrome_password_protection_service.cc

@@ -1317,12 +1317,17 @@ bool ChromePasswordProtectionService::IsPingingEnabled(
     *reason = RequestOutcome::SAFE_BROWSING_DISABLED;
     return false;
   }
+  bool extended_reporting_enabled = IsExtendedReporting();
   if (trigger_type == LoginReputationClientRequest::PASSWORD_REUSE_EVENT) {
     if (password_type.account_type() ==
-        ReusedPasswordAccountType::SAVED_PASSWORD)
-      return IsExtendedReporting() ||
+        ReusedPasswordAccountType::SAVED_PASSWORD) {
+      bool enabled = extended_reporting_enabled ||
                      base::FeatureList::IsEnabled(
                          safe_browsing::kPasswordProtectionForSavedPasswords);
+      if (!enabled)
+        *reason = RequestOutcome::DISABLED_DUE_TO_USER_POPULATION;
+      return enabled;
+    }
 
     PasswordProtectionTrigger trigger_level =
         GetPasswordProtectionWarningTriggerPref(password_type);
@@ -1340,7 +1345,7 @@ bool ChromePasswordProtectionService::IsPingingEnabled(
     *reason = RequestOutcome::DISABLED_DUE_TO_INCOGNITO;
     return false;
   }
-  if (!IsExtendedReporting()) {
+  if (!extended_reporting_enabled) {
     *reason = RequestOutcome::DISABLED_DUE_TO_USER_POPULATION;
     return false;
   }

chrome/browser/safe_browsing/chrome_password_protection_service_unittest.cc

@@ -418,6 +418,7 @@ TEST_F(ChromePasswordProtectionServiceTest,
   EXPECT_FALSE(service_->IsPingingEnabled(
       LoginReputationClientRequest::PASSWORD_REUSE_EVENT, reused_password_type,
       &reason));
+  EXPECT_EQ(RequestOutcome::DISABLED_DUE_TO_USER_POPULATION, reason);
 
   service_->ConfigService(false /*incognito*/, true /*SBER*/);
   EXPECT_TRUE(service_->IsPingingEnabled(